In Power BI, what filters a drill-through page when a reader right-clicks a data point?

## What drill-through is for Summary pages answer "how big" and "which way is it moving". They rarely answer "why", because the rows that explain a number do not fit next to the number. Drill-through solves that by putting the detail on its own page and letting the reader arrive there already filtered to whatever they clicked. ## How the target page declares itself You build the target page normally, then drop one or more fields into the page's **drill-through** well. Those fields are the page's contract: they say "I am a detail page about a Customer" or "about a Product and a Month". Two consequences follow. First, only visuals containing those fields offer the right-click entry. If the page declares `Customer[CustomerName]` and the reader right-clicks a bar on a chart broken out by product, no drill-through to that page is offered, because there is no customer value to pass. This is the most common "why is drill-through greyed out" support ticket. Second, each declared field becomes a filter on the target page, pinned in the filter pane, holding the value that came from the click. The page's own visuals then all see it, because it is a page-level filter like any other. ## Keep all filters Next to the drill-through well sits a **Keep all filters** toggle, on by default. On means the filters that were shaping the *source visual* — page-level filters, slicers, report-level filters, cross-filtering from another visual — travel to the target page as well. Off means only the declared drill-through fields travel. The choice is a real design decision, not a formality. Leave it on when the detail page must show exactly the slice the reader was staring at ("orders for this customer, in the date range and channel I had selected"). Turn it off when the detail page is meant to be a complete profile — "everything we have ever done with this customer, regardless of what page 1 was filtered to". Getting it wrong produces the report bug "drill-through shows fewer rows than the number I clicked", or its mirror, "drill-through shows more than the total". ## Navigation and the back button Power BI adds a back button to a drill-through target automatically, and it returns the reader to the page and state they left. It is worth keeping. Detail pages are usually hidden from the page tab strip so nobody lands on them cold — a hidden page is still reachable by drill-through, and hiding it is the normal pattern. **Cross-report drill-through** extends the idea across reports in the same workspace: the target report enables it, and a source report can then offer navigation into it, passing the shared fields. It depends on the two models sharing field names and on the setting being enabled, so treat it as a deliberate integration rather than an incidental feature. ## Drill-through is not drill-down The vocabulary trips people up. **Drill-down** stays in one visual and walks a hierarchy — Year to Quarter to Month, Country to State to City — using the drill controls in the visual's header; the visual re-queries at the next level. **Drill-through** leaves the visual entirely and navigates to a different page carrying the clicked context. Expand-all is a third thing again: it shows parent and child levels together on one axis. An interviewer asking about drill-through is usually listening for whether you distinguish these three, because a candidate who conflates them will design the wrong thing when asked for "more detail". ## Practical notes and failure modes Drill-through passes *values*, so the field must exist in a table the target page's visuals can be filtered by — the model has to connect them. A detail page built on a table with no relationship to the field being passed will simply ignore the filter and show everything, which looks like a broken page but is a modelling problem. Row-level security still applies on the target page: drill-through never widens what a reader may see, because the filters run inside the model's queries. Finally, put a title on the detail page that echoes the passed value. A page that says "Orders — Contoso Ltd, 2026 Q2" tells the reader what they are looking at and instantly exposes the case where the wrong context travelled.